If Labour is forced to compete with other progressive parties for millions in union funding, it is more likely to listen to what workers want.
Labour leader will say in his TUC speech that Cameron's declaration that trade unions are a "threat to our economy" was reminiscent of Thatcher's "the enemy within" and Romney's "47%".
David Skelton's proposal shows how the Tories could begin to expand their appeal but the PM seems happiest playing the old tunes.
The TUC general secretary says that "before he starts lecturing unions about transparency, the Prime Minister should take a long hard look in the mirror".
Paul Kenny claims he's just doing what Miliband wants but his move was an unambiguous vote of no confidence in the Labour leader's reforms.
Just 25 per cent of the party's funding so far this year has come from affiliated unions, with party members donating most.
The UK's third largest trade union expresses "considerable regret" at Miliband's planned reforms and warns of "further reductions in spending".
With the aid of the Lib Dems, the Tories plan to deliver an even bigger financial hit to Labour than that which will result from Miliband’s trade union reforms.
Should the Labour leader be booed and heckled, as on previous occasions, it will undermine the Tories' claim that he is the plaything of the union leaders.
The trade unions accounted for 77 per cent (£2.4m) of all donations to the party, with just £354,692 received in individual donations.